The tessen, (lit. "Iron Fan" or War Fan), is a folding fan with outer spokes made of heavy plates of iron which were designed to look like normal, harmless folding fans or solid clubs shaped to look like a closed fan.

Samurai could take these to places where swords or other overt weapons were not allowed, and some swordsmanship schools included training in the use of the tessen as a weapon. The tessen was also used for fending off arrows and darts, as a throwing weapon, and as an aid in swimming.

A war fan is a fan designed for use in warfare. Several types of war fans were used by the samurai class of feudal Japan.

Prominent Users

Venus (1997 action figure) comes with a tessen (listed as a "Full-Swing Fan Shield"). As she had no standardized weapon in the series proper outside of magic devices, she is often associated with the tessen in popularity.

As of the events of "Baxter's Gambit", April O'Neil has become armed with a tessen a weapon that Splinter had one day hoped to give to his daughter, Miwa, who April reminds him of. April will now be focusing her fighting style around the real-life Japanese martial art of Tessenjutsu.